There is available a stereoscopic vision technique of allowing stereoscopic viewing of an image by displaying a left-eye image and a right-eye image having an angular difference on a monitor. Stereoscopic vision allows the user to easily grasp the forward/backward relationship between objects and the unevenness information of an object surface, which are difficult to know on a general two-dimensional display. Recently, the stereoscopic vision technique has been applied to the medical field. For example, the user can precisely grasp the positional relationship between neighboring organs, blood vessels, and the like of an object by acquiring a left-eye image and a right-eye image for stereoscopic vision of the object from a specific direction and interpreting a stereoscopic video of the object. Therefore, the stereoscopic vision technique makes it possible to perform safer and more accurate surgical operations and the like. However, the user sometimes wants to stereoscopically view the object from another direction. At this time, the user needs to re-set an imaging angle by, for example, inputting a desired stereoscopic viewing direction. However, for example, during a surgical operation, it is cumbersome for the user to perform the above setting operation for an imaging angle. Acquiring a plurality of images in advance to cope with stereoscopic vision of an object from a plurality of directions can facilitate interpretation of a stereoscopic vision video from another direction with respect to the object. However, acquiring a plurality of images by using an X-ray imaging apparatus or the like will increase the exposure dose of an object.